Some changes to make the application easier to use:

* Replaced the usage of pecl/yaml with symfony/yaml
* simplelinkedin and oauth is now installed via composer
* simplelinkedin is patched upon installation
* autoloading of simplelinkedin and oauth fixed in composer.json
* Updated README to reflect the changes
Merge pull request #1 from christeredvartsen/master

Thanks to christeredvartsen the application is now easier to install.